Latch mechanism



Feb. 23, 1965 c. E. scHuTTl-:r

LATCH MECHANISM 2 sheets-sheet L Filed June 15, 1962 cid' INVENTOR.

C. E. SCHUTTE LATCH MECHANISM Feb. 23, 1965 Filed June 1s, 1962 2Sheets-Sheet 2 INVENTOR.

This inventionrelates to latch mechanisms and more particularly to suchmechanisms as applied toluggagc compartment closures or'the like onvehicle bodies.

The conventional luggage compartment latch mechanism comprises acombination dovetail-housing partially enclosing a latch element havinga keeper engaging por- "tion 'projecting from the housing. The latchelement is releasably held in latched position by some form vof adetent. Disengagement ofthe detent from the latch element isaccomplished through a system of levers arranged to multiplyV theturning force exerted on a key inserted in a key cylinder mechanism. Thelatch mechanism usually incorporates suitable Asprings which function toyieldably hold/the mechanism partis in predetermined positions or torestore the-parts to their original positions after the latchmechanisrhhas been operated. s

An important factor in the acceptability vof such mechanismsforcommercial use is the degree of key torquerequired to turn thekey tocause operation of the system f levers for disengaging the detent fromthe latch element.l The number and placement of the springs used in themechanism has ajdirect bearing on the amount of torque which must beapplied to the key to operate the latch mechanism. l

i' The construction and arrangement of the latch mechanismY embodyingthe present invention has the particular advantage that only one springis utilized to perform the necessary functions of yieldably holdingthelatch mechanism elements in predetermined positionsand ofV restoringelements of the lever` systemand the latch elementto suchV predeterminedpositions after actuation 'of the latch mechanism by operation of a -keyoperated locking and unlocking''device. The abfility of the singlespring to per- `form its vmultiple functions is derived from the.pivotalI relationship of a detent carrying ,lever and of` theV latchelement and of the relationship of a detenton `the detent carryingleverand a detent engageable portion of the latch element. Theserelationships arel such that: (1) When the latch'element is 'inolatchedposition the detent is engagedwith `the detent engageable portion tohold the latch element against movement in unlatching direction, and-(2)when the latch elementis in unlatched position the detentyieldinglyabuts the detent engageable portion to holdthe latch element inunlatched position. l' o l It is an object of the present invention toprovide a simplefcompact, eicient and economical latch mecha.-` nismwhich `vvillmeet all durability'and operationalrequirements'particularly forVl use on automotive vehicles.`

Other objects and advantages'of the present invention Willbe made moreapparent as this description proceeds, particularly when considered inconnection withtheaccompanying drawings, wherein: i o

FIG. 1 is a 'front elevational view of a latch mechanism constructed inaccordance with the present invention, a

portion of the housing cover ,plate being cut away to ex- 'pose thevcomponents of the latch mechanism as they ap-Y pear with the latchelement in unlatched position;`

FIG. 2 is a view in part similar-to FIG. 1 illustrating thecomponentsrof the latch mechanism in lfatched'position;`

FIG; Sis" anenlargedside elevational view looking in the direction ofthe arrow 3 in FIG. 1; and

. FIG'. 4 is an enlarged sectional view taken substantiallyl on theline4L-4 of FIG?.` 1.1

United States Patent 0 The drawings illustratethe latch mechanism,generally designated 11, asit would appear when applied tothe luggagecompartment door of an automobile body, but it will be understood thatthe device is also applicable to other doors and closure members.

The latch mechanism 11 comprises a substantially rectangular housing orcasing, generally designated 12. In the installed position of the `latchmechanism on a vehicle compartment door or deck lidv closure structure,the longitudinal. axis of its housing or casing 12 extends inasubstantially up and` down direction.` The housing or casing V12 has vanintegral inner or rear Wall 13, sidev '1 `he outer or front wall 18, orthe one in spaced rel a-` v t1onsh1p to thewall 13, is an elongatedcover plate which is secured in position to complete the housing afterthe assembly of the latch mechanism components within the housing orcasing 12.` vIt will be noted that the side walls 14 and 15 are taperedat their bottom ends (see FIGS. 2 and 3), for a purpose to be more fullyexplained.

Both'the housing 12 and the cover plate 18 are provided withcomplementary flanges or ears 21 and 22, respectively, extendinglaterally from the sides thereof at the vupper end of each. The llangesare provided with aligned apertures 23 adapted to receive bolts (notshown) or the like for mounting .the latch mechanism on the closurestructure. plate to the housing, the .anges 21 and 22, respectively, arespot welded to each other.

The operating components ofthe latch mechanism 11 AThe lever 24 is anelongated memberwhich is pivotally mounted against the inner face 31 ofthe inner or rear Wall 13 of the housing. `As best` seen in FIG." 4,lever t 24 is mounted on a reduced diameter shoulder portion 32 of pivotshaft 28. `The pivot shaft'28 has a further reduced end portion 33 whichprojects through a hole in the inner.` Wall 13 of the housing and isriveted or staked over as Indicated at 34 for permanent lattachment tothe housing. The pivot shaft` 28 at its other endjhas `an `extension 35adapted to project through a suitableaperture A `V1n 'the cover plate 13and then to lbe riveted or stakedA t over at 36. This, of course,is'done after the latch mechanism-components have been assembledwithinthe housing.

i The spring 26 yieldably urges the lever 24in a clockwise direction asviewed FIGSQl and 2. The-spring 26 is a coil lspringwhich encompassesthe pivot stud 28.V It has-two upstanding free end portions 37 and 38.The

end portion 37 of the spring 26 lies against the inner surface of theside Wall 14 and the end portion 38 hooks over Y the edge-of -the lever24 contiguous to the side-wall 14. Y

The spring 25'is'installedin a preloaded condition.

The latch element 25 comprises a plate member which is pivotally mountedon the shoulder `stud or pivot shaft 'i 29. It will be noted thatrthelatchelement is mountedlinVV i centrally spaced relationship to theinner and outer Walls of the housing. Asp'acer 39 maintains vthe latchelement `in properly spaced-,relationship to the inner wall and ashoulder 41 `on the pivot shaft 29 maintains the proper spacedrelationship tothe outerwall. The pivotv shaft 29y miam-I PatentedPenas, i965 In the iinal assembly of the cover l 3 ends are staked orriveted over at 34 and Se, respectively, as were the ends of the shaft27.

The latch element 25 is provided at one side of its pivot axis withspaced ingers 42 and 43. At its opposite side it is provided with anabutment or projection 44 having on one side thereof a shoulder 45 andon the other side thereof a cam surface 45. The latch element 25 isprovided with a further abutment or extension 47 which in unlatchedcondition of the latch` mechanism, see FIG. 1, engages the side wall ofthe casing to act as a stop limiting the direction of movement of thelatch element in unlatched direction or, as viewed in FG. 1, in aclockwise direction.

Intermediate its ends the lever 24 is provided with an embossed portion48 having a shoulder 49 thereon. The shoulder 49 may hereinafter bereferred to as the detent on the lever 24 and the abutment 44 on thelatch element may hereinafter be referred to as a detent engageableportion of the latch element. As was previously explained, the latchelement is positioned substantially centrally of the walls 13 and 18 andlthe lever 24 is mounted in surface contact with the inner wall 13 ofthe housing. The embossed portion 4S of the lever brings the detent 49into a common plane with the latch element.

The upper end portion 51 of the lever 24 lies in a common plane with thelower end portion and has a ilange 52 which is turned in the directionofthe cover` plate 18. The ange 52 isadapted'to be engaged by the lowerfree end 53 of the actuator cam 27. The actuator cam 27 is pivotallymounted on the cover plate by means of a tubular rivet 55 having asquare or rectangular hole or aperture 56 through its center. Thisactuator cam is adapted to be operated by a conventional key cylindermechanism (not shown) mounted in the outer panel of the closure orcompartment on which the latch mechanism is mounted. It will beunderstood that the key cylinder mechanismincludes a shaft (not shown)which passes through the aperture 56 in the latch actuating cam tubularrivet. A

As seen in FIGS. l and 2, the spaced fingers 42 and 43 which form thelatching portion of the latch element project through an aperture 54 inthe side wall 15 of the housing or casing 12.

The latch mechanism is adapted to have latching engagement with anysuitable striker device which may be mounted on the floor or lowerpanelof a compartment in any desired manner. As far as the present latchmechl' anism is concerned, theV striker is required to havean upper wallportion 57, a fragmentary portion of which is illustrated in thedrawing, having an aperture therein which at one side is defined by adownwardly turned flange 58 and at the other side by an inwardly. anddownwardly turned flange 59. As shown in FIG. 2, the tapered portions ofthe housing or casing side wallsA 14 and 15 will enter the aperture inthe striker wall 57 and act as a pilot to center the latch mechanismwith respect to the striker and thereby the closure with respect to theopening in the compartment.

As seen in FIG. 1, in unlatched position the latch element finger 42iswithin the confines of the side wall 15 of the housing. The latchelement finger 43 lies outside of the contines of the side wall 15 ofthe housing 12 and is adapted to engage the upper surface of thestriker'. Upon downward movement of the housing into the strikeraperture, the engagement of the linger 43 with the upper surface of thestriker causes the latch elementfto be rotated in a clockwise direction.As was pointed outlabove, the spring 26 urges the lever 24 in aclockwise direction toward the latch element 25. As the latch elementrotates in a counterclockwise direction, the lever 24 is forced slightlyto the left or in a counterclockwise direction until the detent 49thereon is able first to surmount the cam surface 46 of the abutment onthe latch element 25 and then to dropinto engagement with` the shoulder45 of the latch element. As soon as this occurs, the latch ele- A 4 ment25 is held against rotation in a clockwise direction by the detent 49 onthe lever 24. The compartment closure is then latched to the compartmentwall.

in order to unlatch the latch mechanism, the actuator cam 27 must beswung in a clockwise direction, by actuation of a key cylinder mechanismas previously described, so that its cam portion'53 will engagethe'upper end of the lever 24 to urge the latter in a 'counterclockawise direction against the resistance of the spring V26. As soon as thedetent portion of the lever 24 is moved Suthciently to the left, or awayfrom the pivot axis of the latch element, the latch element is free torotate, in av clockwise or unlatching direction.

It should be noted that most compartment,closures'l are mounted on hingestructures which include torsion barsor other suitable counterbalancemeans which are effective to cause immediate upwardA movement of theclosure.;

as soon as the latch element is released. This upward movement isusually enough toA cause withdrawal of the latch mechanism suicientlyabove the` plane ofthev striker and rotation of the. latch element to aposition in which the detent cannot reengage the shoulder on the latchelement.

As soon as the actuator cam 27 isl released, that is, as

soon as the key actuating mechanism is no longer being twisted in adirectionA to swing the actuator cam 27 in aclockwise direction, thespringr26 exerts force on the lever 24 to urge the latter in a clockwisedirection. However, one side of the detent on the lever 24 is nowabutting the cam surface 46 on the latch element 25. Thus, the` forceofthe spring tending to urge the lever 24 in a clockwise direction isalso applied to the latch element 25 through the abutting relationshipof the detent 49 and thecam surface 46 of the abutment on the latchelement. As best seen in FIG. 1, the point of contact betweenhthe detentand the cam surface 456 in unlatched position of the latch element 25lies on a line passing above the center of the pivot shaft 29. Theresultant force couple on the latchV element is one which urges thelatch element in a clock'- wise or unlatching direction-at least to theextent permitted by the stop abutment 47. In latched condition of thelatch mechanism the point of vcontact between the v detent 49 and theshoulder 45 on the latch element 25 results in a reaction force'whichlies substantially on a line passing between the pivot axesV of thelatch element 25 and the lever 24. AThe force couple acting` on the.

latch element in latched condition issuch that the latch elementisactually being urged in a counterclockwise direction or latchingcondition. Of course, the latch element and the lever beingnonfyieldablev elements,- the latch elementl is satisfactorily heldinlatched position as a result of the engagement of the detent 49 with theshoulder 45.

Because of the relationship of the pivot centers as dctermined by thepivot axes of the pivot shafts 28 and 29, and because of therelationship ofthe detent.. 49.of the lever 24 with respect'to theabutment 44 on the latch element, only the single spring 26-,is requiredto maintain thev latch element in unlatched position in readiness forlatching engagement with the striker andto hold the lever 24 so that itsdetent 49 is in readiness .to engage the shoulder 45 0n the latchelement when the latter is rotated into latching position afterengagement with the striker. Because of: the mechanical advantageobtained'by the fact that the spring acts on a shorter length of thelever 24 than does the actuator cam 27, the resistance of the`actu'ating cam to being turned by the key is relatively low.

This provides the desirable low key torque which is an importantcriteria of a satisfactory luggage compartment latch mechanism. L

but that various changes and moditicationsamay be made without departingfrom the spirit` and scope of the invcntion as defined in the appendedelaimsjl vergent and being adapted to act as pilot means for Y guidingsaidlatch mechanismlinto latching position relative to a keeperV device,

an elongated lever pivotally mounted at one of its ends Y at said one/endof said housing for swinging movement about a pivot axisintersecting said support',

walls,

said lever extending longitudinally of said housingV along one of saidside walls, i

a latch element pivotally mounted-within said housingY betweensaidelongated lever' and the other of said side walls for swinging movementabout a pivot axis located intermediate the ends ofsaid housing andparallel to said lever pivot axis.

said latch element having a keeper engaging portion at one side thereofprojecting through an aperture in said other side Wall of said housing,a detent on said elongated lever intermediate the ends and on the sidethereof toward said other side Wall, an abutment on said latch elementon the side thereof opposite said keeper engaging portion and in`opposing relation to said detent.

spring means urging said elongated lever and thereby said detent towardsaid other side wall into abutting lrelation to said latch elementabutment,

and an outer manually operabley means pivotally mounted on one of saidsupport walls at the other end of said housing engageable with the otherend of said elongated lever to swing the same and there- Y by saiddetent portion out of latch element holding position. Y

' 2. A latch mechanism comprising:

an elongated housing having spaced support walls and side wallstherebetween, said side walls at one end of said housing beingconvergent and being adapted to act as pilot means for guiding saidlatch mechanism into latching position relative to a keeper device,

an elongated l'ever pivotally mounted at one of its ends s said latchelement having a keeper engaging portion at one side thereof projectingthrough an aperture in said other side wall of said housing,

a detent'portion on said elongated lever intermediate I the ends and onlthe side thereof toward said other side wall, Y t an abutment on saidlatch element on the side thereof opposite said keeper engagingportionand in opposing relation tosaid detent portion, t said detentportion being engageable with one side of said latch element abutment tohold said latch element in latched position and with another side ofsaid vabutment in unlatched position of said latch element, spring meansurging said elongated lever in a direction toV position said detentportion in abutting relation to either side of said abutment,

, the pivotal relationship of lsaid lever and said latch element and therelationship of said detent portion and said one side of said abutmentwhensaid latch element is in latched lposition beingsuch that the'fo'rcet exerted by said detent portion on said abutment'acts latch elementpivot axis and between the lever and latch element pivot axes. 1

' 3. Alatch mechanism comprising:l v y. `an elongated housinghaving-spaced supportwalls .and side walls therebetween,` a said sideWalls at one endf'of said housing being convergent and being adapted toact as pilot means for guidingsa'id latch mechanism intolatchingposition'relaj tive toakeeper device,\ 5'

an elongated lever pivotally mounted at one of its ends `at said one endof said housing for swinging movement about `a pivot axis .intersecting7 said support Walls, l said leverrextending longitudinally of saidhousing adjacent one of said side walls, f a latch element pivotallymounted Within said housing between said elongated lever and the otherof said side walls for swinging movement about a pivot axis locatedintermediate the ends of said housing and paralf lel to said lever pivotaxis,

said latch element having a keeper engaging portion at one side thereofprojecting through an aperture in said other side Wall of said housing,

a detent portion on said elongated lever intermediate the ends and onthe side thereof toward said other side wall,

an abutment on said latch element on the side thereof opposite saidkeeper engaging portion and in opposing relation to said detent portion,

`said detent portion being engageable `with one side of said latchelement abutment to hold said latch element in latched position and withanother side of said abutment in unlatched position of said latchelement,

spring means urging said elongated lever in a direction to position saiddetent portion in abutting relation to either side of said abutment,

the pivotal relationship of said lever and said latch ele- 'Y side ofsaid abutment whenl s aid'latch element is held in unlatched positionbeing such that the force exerted by said detent portion on saidabutment acts -substantially along a line passing to the other side ofsaid latch element pivot axis. v

4'. A latch mechanism comprising:

an elongated housing having spaced support walls and side wallstherebetween, Y

said side walls at one end ofA said housing being convergent and beingadapted to act as pilot means for i Y guiding said ,latch mechanismintolatching position relative to a keeper device, 7 Y

an elongated lever pivotally'mounted at one of its ends at one end ofsaid housing for swingingfmovement about a pivot axisintersecting saidsupport walls,

said lever extending longitudinally of said housing adjacent one of saidside walls,

a latch element pivotally mounted within said housing between saidelongated lever and the other of said side Walls for swinging movementabout a pivot axis located. intermediate lthe ends of said housing andparallel to said lever pivot axis,

said latch `element having a keeper engaging portion at one sidethereofprojecting through an aperture in said' other side Wall of said housing,j

a ydetent portion on said elongated lever intermediate the ends and Vonthe side thereof toward said other side wall,

an abutment `on said latch element on the side thereof opposite saidkeeper engaging portion and in opposing relation totsaiddetent portion,

said detent portion being engageable with one, side of said latchelement abutment to hold said'latch element in'latched position and Withanother side'of said abutment in unlatched position of saidlatch-element,

spring means urging said elongated lever in a direction to position saiddetent in abutting relation toeither side of said abutment,`

the pivotal relationship of said'lever and said'latchfelement and v t f(1) the relationship of said detent portiony and said one side of saidabutment being such that when said latch element is in latched positionsaid detent portion holds said latch element against movement inunlatehing direction, and

' outer manually operable means pivotally mounted on one (2) therelationship of said detent and said other side of said abutment beingsuch that'when said latch element is in uulatched position said detentyieldingly holds said latch element in said unlatched position.

5. A latch-mechanism according to claim 4 having an or said supportwalls for engagement with the other end of said elongated lever to swingthe same out of latch element holding position.

References Cited in the le of this patent UNITED STATES PATENTS 560,888Ayars May 26, 1896 2,393,647V Marple Jan. 29, 1946 2,544,682 HilgemanMar. 13., 1951 3,016,968 Lenz et al Jan. 16, 1962

1. A LATCH MECHANISM COMPRISING: AN ELONGATED HOUSING SPACED SUPPORTWALL AND SIDE WALLS THEREBETWEEN, SAID SIDE WALLS AT ONE END OF SAIDHOUSING BEING CONVERGENT AND BEING ADAPTED TO ACT AS PILOT MEANS FORGUIDING SAID LATCH MECHANISM INTO LATCHING POSITION RELATIVE TO A KEEPERDEVICE, AN ELONGATED LEVER PIVOTALLY MOUNTED AT ONE OF ITS ENDS AT SAIDONE END OF SAID HOUSING FOR SWINGING MOVEMENT ABOUT A PIVOT AXISINTERSECTING SAID SUPPORT WALLS, SAID LEVER EXTENDING LONGITUDINALLY OFSAID HOUSING ALONG ONE OF SAID SIDE WALLS, A LATCH ELEMENT PIVOTALLYMOUNTED WITHIN SAID HOUSING BETWEEN SAID ELONGATED LEVER AND THE OTHEROF SAID SIDE WALLS FOR SWINGING MOVEMENT ABOUT A PIVOT AXIS LOCATEDINTERMEDIATE THE ENDS OF SAID HOUSING AND PARALLEL TO SAID LEVER PIVOTAXIS. SAID LATCH ELEMENT HAVING A KEEPER ENGAGING PORTIONM AT ONE SIDETHEREOF PROJECTING THROUGH AN APERTURE IN SAID OTHER SIDE WALL OF SAIDHOUSING, A DETENT ON SAID ELONGATED LEVER INTERMEDIATE THE ENDS AND ONTHE SIDE THEREOF TOWARD SAID OTHER SIDE WALL, AN ABUTMENT ON SAID LATCHELEMENT ON THE SIDE THEREOF OPPOSITE SAID KEEPER ENGAGING PORTION AND INOPPOSING RELATION TO SAID DETENT. SPRING MEANS URGING SAID ELONGATEDLEVER AND THEREBY SAID DETENT TOWARD SAID OTHER SIDE WALL INTO ABUTTINGRELATION TO SAID LATCH ELEMENT ABUTMENT, AND AN OUTER MANUALLY OPERABLEMEANS PIVOTALLY MOUNTED ON ONE OF SAID SUPPORT WALLS AT THE OTHER END OFSAID HOUSING ENGAGEABLE WITH THE OTHER END OF SAID ELONGATED LEVER TOSWING THE SAME AND THEREBY SAID DETENT PORTION OUT OF LATCH ELEMENTHOLDING POSITION.